-- when 4 chars is received.
    uart.on("data", 4, 
      function(data)
        print("receive from uart:", data)
        if data=="quit" then 
          uart.on("data") 
        end        
    end, 0)
    -- when '\r' is received.
    uart.on("data", "\r", 
      function(data)
        print("receive from uart:", data)
        if data=="quit\r" then 
          uart.on("data") 
        end        
    end, 0)


local f = loadstring(thecode)if f then
    f()
else    print ">>> Invalid Lua code <<<"end